The decoking control valve is installed on the outlet pipe of the jet pump at the bottom of the coke drum, and the water inlet of the decoking control valve is connected with the outlet of the jet pump. The decoking control valve controls the output flow of the jet pump through the three positions/settings and has three operating modes as per below
Recirculation: Bypass mode, flow control for pump protection.
Pre-fill: Low pressure pre-fill sequence to fill the system lines to avoid water hammer.
Full flow: Decoking mode with full flow and low pressure drop.